How elasmobranchs sense their environment
A detailed synthesis of the
physiology of elasmobranchs, comparing them to other fish groups and
highlighting areas of future research interest and prospective
Research Paper: Collin SP, Kempster RM and Yopak KE (2015) How Elasmobranchs Sense their Environment. In: (Shadwick RE, Farrell AP and Brauner CJ eds.) Physiology of Elasmobranch Fishes: Structure and Interaction with Environment. Academic Press 34(1): 422
A review of the effectiveness of international protection for White sharks, Basking sharks and Whale sharks.
There has been a rapid decline in populations of many shark species, while new science has emerged of the critical role they play in marine ecosystems. Here we show that conservation law and policy have been slow to develop, with only a small number of iconic species being protected worldwide. The increase in fishing impact – primarily through shark finning and by-catch - has led to shark conservation receiving greater international attention in recent years. This book explores our current knowledge and status of the law and science in relation to sharks with a particular focus on improving frameworks for their conservation and management.
Rare shark species discovered in Western Australia
The mandarin dogfish, Cirrhigaleus barbifer, is the only species in this genus found in Western Australia, and represents a significant range extension and first record in Australia. Most Cirrhigaleus sharks are clearly separable from other squalid sharks by the presence of conspicuous barbels on the anterior nasal flaps. Cirrhigaleus barbifer may be distinguished from its close relative C. australis by the structure of the CO1 gene and key measurements. In addition, this is only the second record of a gravid female of C. barbifer, with pups in an advanced stage of development. New data on the reproductive biology and range of C. barbifer are included.
Research Paper: Kempster RM, Hunt DM, Human BA, Egeberg CA, Collin SP (2013) First record of the mandarin dogfish Cirrhigaleus barbifer (Chondrichthyes: Squalidae) from Western Australia. Marine Biodiversity Records
Assessing the potential for post-copulatory sexual selection in elasmobranchs
This review highlights the potential role that post-copulatory sexual selection plays in elasmobranch reproductive systems and the utility of this group to further understanding of evolutionary responses to the post-copulatory processes of sperm competition and cryptic female choice. The growing genetic evidence for female multiple mating (polyandry) in elasmobranchs is summarized. While polyandry appears to be common in this group, rates of multiple paternity are highly variable between species suggesting that there is large variance in the strength of post-copulatory sexual selection among elasmobranchs. Possible adaptations of traits important for post-copulatory sexual selection are then considered. Particular emphasis is devoted to explore the potential for sperm competition and cryptic female choice to influence the evolution of testes size, sperm morphology, genital morphology and sperm storage organs. Finally, it is argued that future work should take advantage of the wealth of information on these reproductive traits already available in elasmobranchs to gain a better understanding of how post-copulatory sexual selection operates in this group.
Associated media coverage: UWA News...Research Paper: Fitzpatrick JL, Kempster RM, Daly-Engel TS, Collin SP, Evans JP (2012) Assessing the potential for post-copulatory sexual selection in elasmobranchs. Journal of Fish Biology 80: 1141-1158.
Dietary partitioning by five sympatric stingrays (Dasyatidae) at Ningaloo Reef, Western Australia
Stingrays form an important component of the fish fauna of coastal marine ecosystems. We examined the diet and feeding preferences of five species (Pastinachus atrus, Taeniura lymma, Neotrygon kuhlii, Urogymnus asperrimus and Himantura uarnak) of sympatric stingray (Dasyatidae) within a coral reef lagoon at Ningaloo, Western Australia. This study provides the first data on the role of stingrays, as predators, in this unique coral reef ecosystem.
Associated media coverage: ABC News...
Feeding behaviour of the basking shark
The basking shark Cetorhinus maximus is the second largest fish in the world, attaining lengths of up to 10 m. Very little is known of its sensory biology, particularly in relation to its feeding behaviour. We describe the abundance and distribution of ampullary pores over the head and propose that both the spacing and orientation of electrosensory pores enables C. maximus to use passive electroreception to track the diel vertical migrations of zooplankton that enable the shark to meet the energetic costs of ram filter feeding.
Associated media coverage: Australian Geographic...
Feeding behaviour of the megamouth shark
The megamouth shark Megachasma pelagios is a rare, large filter-feeding shark. Little to nothing is known of its sensory biology, particularly in relation to its feeding behaviour. We describe the abundance and distribution of ampullary pores over the head and propose that both the spacing and orientation of electrosensory pores enables M. pelagios to use passive electroreception to maximise feeding efficiency.